How to control the interval and size of continuous legend bar

[Ellenz]

My question is similar to this post, but how to increase the interval of the color bar display? Thanks.

How to change the legend title using geom_tile

My question is how to change the title of the ggplot legend. It seems an easy question, but I have tried various ways and still couldn't get it correct. wd.files <- c("wind_39.9375_-105.3125"," wind_39.9375_-105.4375", "wind_40.0625_-105.3125", "wind_40.0625_-105.4375") In each txt file, such as "wind_39.9375_-105.3125", there are annual average wind speed from 1950 to 2000, formatted like the following: 2.5 3.0 5.1 4.4 ... I have combined all the txt files together (each file represents wind speed at that grid cell), and got the dataset with three columns: longitude, latitude, and wind speed (at the specific grid cell). I use the code below to plot the surface, but don…

For example, if the color bar is displayed as in the figure, how to have the interval of 2 m/s, or 0.5 m/s, rather than every 1 m/s? Thanks very much.